1. Bare bones. Pure utility, any styling is simply for readability. Craigslist style.

2. Big, garish, bold; sometimes called Nu-brutalism or Sportsbrut.

I should note that each of these has very little, if anything, to do with the 20th century architectural trend, which focused on applying usage of basic shapes and raw materials at a large scale. On the web, the "raw materials" part is the only real connection to the origins of the term, with the first one focused on lofi design with basic tooling, and the second highlighting garish things you can do with basic forms.

Neo-brutalism is another trend to note; think of it as a focus on raw shapes with some niceties added on top to make things more interesting.

Links:

1. https://www.smashingmagazine.com/2020/01/split-personality-b...

2. https://medium.com/@sepidy/how-can-i-design-in-the-neo-bruta...